Such oil separators are already used in oil-injected compressors, whereby the oil-gas mixture leaving the outlet of the compressor element is guided to the oil separator before being guided to consumers of compressed gas for example.
In the oil separator the oil-gas mixture to be treated is brought into the space between the screen and the housing via the inlet in the housing, in which pace the oil-gas mixture will flow so that a first separation phase takes place.
Then the oil-gas mixture will undergo a second separation phase when the oil-gas mixture is forced to flow around the end of the screen to the space enclosed by the screen and thus to change direction in this way.
The separated oil will be collected in the housing of the oil separator at the bottom thereof.
The oil-gas mixture will subsequently flow through the filter element, whereby the oil-gas mixture will finally arrive in the interior of the filter element.
The filter element can consist of a casing that is provided with a suitable filter material that is closed off by the lid of the housing and a bottom. In other words the filter element is attached to the lid of the housing to ensure that the filter element is firmly fastened in the housing of the oil separator.
When flowing through the filter element, a third separation phase takes place, whereby the separated oil is collected in the bottom.
The thus purified gas is brought from the inside to the outlet in the housing via the pipe of collector, where it is guided to consumers of compressed gas.
The filter element of the separator can be replaced for maintenance by removing the lid on the top of the oil separator.
Because in the known oil separators the filter element is attached to the lid of the housing, the removal and refitting of this lid is a delicate operation that comes with a risk of damaging or misplacement of the filter element.
It is known that the gas that flows around in the oil separator can generate static electricity, such that parts in the housing can become statically changed.
An insulated part that is charged can discharge at a certain time, whereby this discharge is coupled with a spark.
This spark can cause an explosion, which can cause severe damage to the machine and can also mean a serious danger for bystanders.
In the known oil separators the filter element is often insulated from the rest of the oil separator.
This occurs because the filter element forms a separation between the oil-gas mixture outside the filter element, i.e. after the second but before the third separation phase, and the gas in the interior of the filter element after the third phase.
For this reason seals are used, for example between the bottom and the pipe or between the lid and the costing, which seals are made from a non-conductive material such as fluoroelastomer (FKM), polytetrafluoroethylene (PTFE), nitrile butadiene rubber (NBR).
As a result the filter element is insulated from the rest of the oil separator. Consequently there is a risk that the filter element will become statically charged during use.